1. Field of the Invention
This invention relates generally to controlling a PCI bus signal in a computer system, and, more particularly, to the control of a REQ64# signal used to indicate to a plug-in board the type of a system in which it is installed.
2. Description of the Related Art
The proliferation of computers has affected virtually every aspect of our personal and business lives. Whereas large mainframes and so-called minicomputers once ruled the computer world, the technology has advanced rapidly over the last 20 years. Today, due in large part to the development and sophistication of the microprocessor, personal computers in the form of desktops and laptops, for example, have completely supplanted the larger machines in many applications. Personal computers, used in stand-alone or network environments, are commonplace.
When personal-computers are ganged together into a network, typically a server, which may be a personal computer in itself, will serve as the hub of the network. Generally, each of the personal computers in the network will have access to the server. The server can be used for a variety of functions, for example, to store and run application programs for each of the personal computers in the network, or simply to function as a storehouse for data files to which each of the personal computers in the network may have access. In a network environment, the server is one of the more important elements. For example, if one of the personal computers in the network will not operate, the network as a whole will not be significantly affected. On the other hand, if the server will not operate, the information it stores, whether application programs or data files, will not be accessible to the personal computers, and a primary purpose for the existence of the network will be frustrated.
Because of the heavy reliance on computers, particularly in our business lives, computer downtime may be very costly. Downtime may result not only from unexpected hardware or software problems but from periodic maintenance as well as periodic system upgrade. When one computer in a network is inoperative, a costly situation exists. But when the server in a network is not functional, the severity of the situation is exacerbated. To the extent possible, this downtime should be minimized.
A technology, referred to as "PCI hot plug" technology, has been developed to minimize downtime associated with system maintenance, whether planned or otherwise. "PCI hot plug" capability refers to an ability to remove, add, or replace component boards of a computer without turning off the computer. For example, when a new component board is inserted into an empty slot in the running computer, various control signals are generated so that the computer will recognize the existence and type of the new board. While this technology has been employed in 32-bit systems, the control signals associated with 64-bit systems differ from those associated with the 32-bit systems. Thus, if a 64-bit board is added to a system using the current technology, the board will think it is installed in a 32-bit system instead of in a 64-bit system.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.